de.caff.util

Class FileTool

java.lang.Object

de.caff.util.FileTool

public final class FileTool
extends java.lang.Object

Helper tools for handling files.

Since:

March 05, 2019

Author:

Rammi

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.Comparator<java.io.File>	BY_NAME_CASE_INSENSITIVE Sort by name (case insensitive).
static java.util.Comparator<java.io.File>	BY_NAME_CASE_SENSITIVE Sort by name (case sensitive).
static java.util.Comparator<java.io.File>	DIRECTORIES_FIRST Sort directories first.
static long	NO_DIFFERENCE Return value of firstDiff(File, File) when both contents are equal.

Method Summary

Modifier and Type	Method and Description
static void	append(java.io.File file, byte[] data) Append the given bytes to a file.
static void	append(java.io.File file, byte[] data, int offset, int length) Append the given bytes to a file.
static void	append(java.lang.String file, byte[] data) Append the given bytes to a file.
static void	append(java.lang.String file, byte[] data, int offset, int length) Append the given bytes to a file.
static boolean	cleanup(java.io.File dir) Cleanup a directory by removing its content.
static boolean	contentEquals(java.io.File file1, java.io.File file2) Is the content of two files equal?
static boolean	contentEquals(java.nio.file.Path file1, java.nio.file.Path file2) Is the content of two files equal?
static boolean	contentEquals(java.lang.String filePath1, java.lang.String filePath2) Is the content of two files equal?
static boolean	deleteTree(java.io.File file) Delete a file or file tree.
static java.io.File	expand(java.io.File dir, java.lang.String... subPath) Append multiple path items to a file.
static long	firstDiff(java.io.File file1, java.io.File file2) Get the position of the first difference of the content of two files.
static long	firstDiff(java.lang.String filePath1, java.lang.String filePath2) Get the position of the first difference of the content of two files.
static java.lang.String	getExtension(java.io.File file) Get the extension of the file name.
static java.lang.String	getExtension(java.lang.String fileName) Get the extension of the file name.
static byte[]	load(java.io.File file) Load a file into memory.
static byte[]	load(java.lang.String file) Load a file into memory.
static java.io.File	multiExpand(java.io.File dir, char fileSeparator, java.lang.String subPath) Append a complete path to a file.
static java.io.File	multiExpand(java.io.File dir, java.lang.String subPath) Append a complete path to a file.
static java.util.List<java.io.File>	performGlobbing(java.io.File fileWithPossibleGlobbing)
static void	store(java.io.File file, byte[] data) Store the given bytes to a file.
static void	store(java.io.File file, byte[] data, int offset, int length) Store the given bytes to a file.
static void	store(java.lang.String file, byte[] data) Store the given bytes to a file.
static void	store(java.lang.String file, byte[] data, int offset, int length) Store the given bytes to a file.
static void	walkTree(java.io.File file, java.util.function.Consumer<? super java.io.File> fileHandler) Walk a file tree.
static void	walkTree(java.io.File file, java.util.function.Predicate<? super java.io.File> stepIntoDir, java.util.function.Consumer<? super java.io.File> fileHandler) Walk a file tree.
static <E extends java.lang.Exception> void	walkTreeFragile(java.io.File file, FragileProcedure1<E,? super java.io.File> fileHandler) Walk a file tree and apply a consumer which might throw an exception.
static <E extends java.lang.Exception> void	walkTreeFragile(java.io.File file, java.util.function.Predicate<java.io.File> stepIntoDir, FragileProcedure1<E,? super java.io.File> fileHandler) Walk a file tree and apply a consumer which might throw an exception.
static void	walkTreeOrdered(java.io.File file, java.util.function.Consumer<? super java.io.File> fileHandler, java.util.Comparator<? super java.io.File> order) Walk a file tree in a defined order.
static void	walkTreeOrdered(java.io.File file, java.util.function.Predicate<? super java.io.File> stepIntoDir, java.util.function.Consumer<? super java.io.File> fileHandler, java.util.Comparator<? super java.io.File> order) Walk a file tree in a defined order.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DIRECTORIES_FIRST

public static final java.util.Comparator<java.io.File> DIRECTORIES_FIRST

Sort directories first.

Ignores names.

Use Comparator.thenComparing(Comparator) with BY_NAME_CASE_INSENSITIVE or BY_NAME_CASE_SENSITIVE to get directories first, while names are ordered inside each group.

Use Comparator.reversed() for the reverse of this.

BY_NAME_CASE_INSENSITIVE

public static final java.util.Comparator<java.io.File> BY_NAME_CASE_INSENSITIVE

Sort by name (case insensitive).

Directories and files are mixed.

Use Comparator.reversed() to reverse this order.

See Also:

DIRECTORIES_FIRST

BY_NAME_CASE_SENSITIVE

public static final java.util.Comparator<java.io.File> BY_NAME_CASE_SENSITIVE

Sort by name (case sensitive).

Directories and files are mixed.

Use Comparator.reversed() to reverse this order.

See Also:

DIRECTORIES_FIRST

NO_DIFFERENCE

public static final long NO_DIFFERENCE

Return value of firstDiff(File, File) when both contents are equal.

See Also:

Constant Field Values

Method Detail

walkTree

public static void walkTree(@NotNull
                            java.io.File file,
                            @NotNull
                            java.util.function.Predicate<? super java.io.File> stepIntoDir,
                            @NotNull
                            java.util.function.Consumer<? super java.io.File> fileHandler)

Walk a file tree. This walks through the tree in depth-first order. Symbolic links are not handled specially. Files in a directory are encountered in 'natural' order.

Parameters:

file - file to start with, usually a directory

stepIntoDir - Predicate allowing to avoid directories. Always called with a directory, i.e. file.isDirectory() is always true.

fileHandler - Handler called for each file. File is never a directory, i.e. file.isDirectory() is always false.

walkTree

public static void walkTree(@NotNull
                            java.io.File file,
                            @NotNull
                            java.util.function.Consumer<? super java.io.File> fileHandler)

Walk a file tree. This walks through the tree in depth first order. Symbolic links are not handled specially. This steps into every directory found. Files in a directory are encountered in 'natural' order.

Parameters:

file - file to start with, usually a directory

fileHandler - Handler called for each file. File is never a directory, i.e. file.isDirectory() is always false.

walkTreeOrdered

public static void walkTreeOrdered(@NotNull
                                   java.io.File file,
                                   @NotNull
                                   java.util.function.Predicate<? super java.io.File> stepIntoDir,
                                   @NotNull
                                   java.util.function.Consumer<? super java.io.File> fileHandler,
                                   @NotNull
                                   java.util.Comparator<? super java.io.File> order)

Walk a file tree in a defined order. This walks through the tree in depth first order. Symbolic links are not handled specially. Files in a directory are encountered in the defined order.

Parameters:

file - file to start with, usually a directory

stepIntoDir - Predicate allowing to avoid directories. Always called with a directory, i.e. file.isDirectory() is always true.

fileHandler - Handler called for each file. File is never a directory, i.e. file.isDirectory() is always false.

order - comparator defining the order in which files inside a directory are handled. Common orders can be defined by combining the comparators DIRECTORIES_FIRST, BY_NAME_CASE_INSENSITIVE, and BY_NAME_CASE_SENSITIVE.

walkTreeOrdered

public static void walkTreeOrdered(@NotNull
                                   java.io.File file,
                                   @NotNull
                                   java.util.function.Consumer<? super java.io.File> fileHandler,
                                   @NotNull
                                   java.util.Comparator<? super java.io.File> order)

Walk a file tree in a defined order. This walks through the tree in depth first order. Symbolic links are not handled specially. This steps into every directory found. Files in a directory are encountered in 'natural' order.

Parameters:

file - file to start with, usually a directory

fileHandler - Handler called for each file. File is never a directory, i.e. file.isDirectory() is always false.

order - comparator defining the order in which files inside a directory are handled. Common orders can be defined by combining the comparators DIRECTORIES_FIRST, BY_NAME_CASE_INSENSITIVE, and BY_NAME_CASE_SENSITIVE.

walkTreeFragile

public static <E extends java.lang.Exception> void walkTreeFragile(@NotNull
                                                                   java.io.File file,
                                                                   @NotNull
                                                                   java.util.function.Predicate<java.io.File> stepIntoDir,
                                                                   @NotNull
                                                                   FragileProcedure1<E,? super java.io.File> fileHandler)
                                                            throws E extends java.lang.Exception

Walk a file tree and apply a consumer which might throw an exception. This walks through the tree in depth-first order. This allows to exclude or react on directories. Symbolic links are not handled specially. Files in a directory are encountered in 'natural' order.

Type Parameters:

E - exception thrown by fragile procedure, forwarded by this method

Parameters:

file - file to start with, usually a directory

stepIntoDir - Predicate allowing to avoid directories. Always called with a directory, i.e. file.isDirectory() is always true, before stepping into that directory.

fileHandler - Handler called for each file. File is never a directory, i.e. file.isDirectory() is always false.

Throws:

E - when fileHandler throws it

E extends java.lang.Exception

walkTreeFragile

public static <E extends java.lang.Exception> void walkTreeFragile(@NotNull
                                                                   java.io.File file,
                                                                   @NotNull
                                                                   FragileProcedure1<E,? super java.io.File> fileHandler)
                                                            throws E extends java.lang.Exception

Walk a file tree and apply a consumer which might throw an exception. This walks through the tree in depth-first order. Symbolic links are not handled specially. Files in a directory are encountered in 'natural' order.

Type Parameters:

E - exception thrown by fragile procedure, forwarded by this method

Parameters:

file - file to start with, usually a directory

fileHandler - Handler called for each file. File is never a directory, i.e. file.isDirectory() is always false.

Throws:

E - when fileHandler throws it

E extends java.lang.Exception

getExtension

@Nullable
public static java.lang.String getExtension(@NotNull
                                                      java.io.File file)

Get the extension of the file name.

Parameters:

file - file with a possible extension

Returns:

everything after the last dot of the filename, possibly empty it the file ends with a dot, or null if the name does not contain any dots

getExtension

@Nullable
public static java.lang.String getExtension(@NotNull
                                                      java.lang.String fileName)

Get the extension of the file name.

Parameters:

fileName - file name with a possible extension

Returns:

everything after the last dot of the filename, possibly empty it the file ends with a dot, or null if the name does not contain any dots

contentEquals

public static boolean contentEquals(@NotNull
                                    java.io.File file1,
                                    @NotNull
                                    java.io.File file2)
                             throws java.io.IOException

Is the content of two files equal?

Parameters:

file1 - first file

file2 - second file

Returns:

true if both files have the same content
false if both files have different content

Throws:

java.io.IOException - on file open or read errors

contentEquals

public static boolean contentEquals(@NotNull
                                    java.nio.file.Path file1,
                                    @NotNull
                                    java.nio.file.Path file2)
                             throws java.io.IOException

Is the content of two files equal?

Parameters:

file1 - first file

file2 - second file

Returns:

true if both files have the same content
false if both files have different content

Throws:

java.io.IOException - on file open or read errors

contentEquals

public static boolean contentEquals(@NotNull
                                    java.lang.String filePath1,
                                    @NotNull
                                    java.lang.String filePath2)
                             throws java.io.IOException

Is the content of two files equal?

Parameters:

filePath1 - path of first file

filePath2 - path of second file

Returns:

true if both files have the same content
false if both files have different content

Throws:

java.io.IOException - on file open or read errors

firstDiff

public static long firstDiff(@NotNull
                             java.io.File file1,
                             @NotNull
                             java.io.File file2)
                      throws java.io.IOException

Get the position of the first difference of the content of two files.

Parameters:

file1 - first file

file2 - second file

Returns:

first position where both files differ, or NO_DIFFERENCE if both files have the same content

Throws:

java.io.IOException - on file open or read errors

firstDiff

public static long firstDiff(@NotNull
                             java.lang.String filePath1,
                             @NotNull
                             java.lang.String filePath2)
                      throws java.io.IOException

Get the position of the first difference of the content of two files.

Parameters:

filePath1 - path of first file

filePath2 - path of second file

Returns:

first position where both files differ, or NO_DIFFERENCE if both files have the same content

Throws:

java.io.IOException - on file open or read errors

load

@NotNull
public static byte[] load(@NotNull
                                   java.io.File file)
                            throws java.io.IOException

Load a file into memory.

Parameters:

file - file to load

Returns:

byte array with file content

Throws:

java.io.IOException - on read errors or if the file is too large to fit into a byte array

See Also:

load(String)

load

@NotNull
public static byte[] load(@NotNull
                                   java.lang.String file)
                            throws java.io.IOException

Load a file into memory.

Parameters:

file - file to load

Returns:

byte array with file content

Throws:

java.io.IOException - on read errors or if the file is too large to fit into a byte array

See Also:

load(File)

store

public static void store(@NotNull
                         java.io.File file,
                         @NotNull
                         byte[] data)
                  throws java.io.IOException

Store the given bytes to a file. There are no safety belts, the file will ve overwritten if it exists.

Parameters:

file - file to write to

data - data to write

Throws:

java.io.IOException - on write errors

store

public static void store(@NotNull
                         java.io.File file,
                         @NotNull
                         byte[] data,
                         int offset,
                         int length)
                  throws java.io.IOException

Store the given bytes to a file. There are no safety belts, the file will ve overwritten if it exists.

Parameters:

file - file to write to

data - data to write

offset - start offset into the byte array

length - number of bytes to be written

Throws:

java.io.IOException - on write errors

store

public static void store(@NotNull
                         java.lang.String file,
                         @NotNull
                         byte[] data)
                  throws java.io.IOException

Store the given bytes to a file. There are no safety belts, the file will ve overwritten if it exists.

Parameters:

file - file to write to

data - data to write

Throws:

java.io.IOException - on write errors

store

public static void store(@NotNull
                         java.lang.String file,
                         @NotNull
                         byte[] data,
                         int offset,
                         int length)
                  throws java.io.IOException

Store the given bytes to a file. There are no safety belts, the file will ve overwritten if it exists.

Parameters:

file - file to write to

data - data to write

offset - start offset into the byte array

length - number of bytes to be written

Throws:

java.io.IOException - on write errors

append

public static void append(@NotNull
                          java.io.File file,
                          @NotNull
                          byte[] data)
                   throws java.io.IOException

Append the given bytes to a file.

Parameters:

file - file to append to

data - data to append

Throws:

java.io.IOException - on write errors

append

public static void append(@NotNull
                          java.io.File file,
                          @NotNull
                          byte[] data,
                          int offset,
                          int length)
                   throws java.io.IOException

Append the given bytes to a file.

Parameters:

file - file to append to

data - data to append

offset - start offset into the byte array

length - number of bytes to be written

Throws:

java.io.IOException - on write errors

append

public static void append(@NotNull
                          java.lang.String file,
                          @NotNull
                          byte[] data)
                   throws java.io.IOException

Append the given bytes to a file.

Parameters:

file - file to append to

data - data to append

Throws:

java.io.IOException - on write errors

append

public static void append(@NotNull
                          java.lang.String file,
                          @NotNull
                          byte[] data,
                          int offset,
                          int length)
                   throws java.io.IOException

Append the given bytes to a file.

Parameters:

file - file to append to

data - data to append

offset - the start offset into the byte array

length - number of bytes to be written

Throws:

java.io.IOException - on write errors

deleteTree

public static boolean deleteTree(@NotNull
                                 java.io.File file)

Delete a file or file tree.

If removing fails for whatever reason, further processing is stop and false returned.

Parameters:

file - file or directory

Returns:

true if deletion is complete
false if deletion of the file or the tree (partially) failed

cleanup

public static boolean cleanup(@NotNull
                              java.io.File dir)

Cleanup a directory by removing its content. If dir is not a directory, nothing will be deleted. If removing fails for whatever reason, further processing is stop and false returned.

Parameters:

dir - directory

Returns:

true if cleanup is complete
false if cleanup of the directory (partially) failed

multiExpand

@NotNull
public static java.io.File multiExpand(@NotNull
                                                java.io.File dir,
                                                @NotNull
                                                java.lang.String subPath)

Append a complete path to a file. This method expects the system's default as a file separator.

Parameters:

dir - directory where paths are

subPath - sub path, has to be relative

Returns:

evaluated file/directory

multiExpand

public static java.io.File multiExpand(@NotNull
                                       java.io.File dir,
                                       char fileSeparator,
                                       @NotNull
                                       java.lang.String subPath)

Append a complete path to a file.

Parameters:

dir - directory where paths are

fileSeparator - file separator char, usually either '/' or `\\`

subPath - sub path, has to be relative

Returns:

evaluated file/directory

expand

public static java.io.File expand(@NotNull
                                  java.io.File dir,
                                  @NotNull
                                  java.lang.String... subPath)

Append multiple path items to a file.

Parameters:

dir - directory where paths are

subPath - The sub path. User has to take care that the sub paths are valid file names and don't contain separator characters.

Returns:

evaluated file/directory

performGlobbing

@NotNull
public static java.util.List<java.io.File> performGlobbing(@NotNull
                                                                    java.io.File fileWithPossibleGlobbing)
                                                             throws java.io.IOException

Throws:

java.io.IOException